Recovery of Cognitive Function After Surgery for Aneurysmal Subarachnoid Hemorrhage

Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage (IMASH)

Background and Purpose— Pilot clinical trials using magnesium sulfate in patients with acute aneurysmal subarachnoid hemorrhage have reported trends toward improvement in clinical outcomes. This Phase III study aimed to compare intravenous magnesium sulfate infusion with saline placebo among such patients.

Methods— We recruited patients with aneurysmal subarachnoid hemorrhage within 48 hours of onset from 10 participating centers. The patients were randomly assigned to magnesium sulfate infusion titrated to a serum magnesium concentration twice the baseline concentration or saline placebo for 10 to 14 days. Patients and assessors were blinded to treatment allocation. The study is registered at www.strokecenter.org/trials (as Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage [IMASH]) and www.ClinicalTrials.gov (NCT00124150).

Results— Of the 327 patients recruited, 169 were randomized to receive treatment with intravenous magnesium sulfate and 158 to receive saline (placebo). The proportions of patients with a favorable outcome at 6 months (Extended Glasgow Outcome Scale 5 to 8) were similar, 64% in the magnesium sulfate group and 63% in the saline group (OR, 1.0; 95% CI, 0.7 to 1.6). Secondary outcome analyses (modified Rankin Scale, Barthel Index, Short Form 36, and clinical vasospasm) also showed no significant differences between the 2 groups. Predefined subgroups included age, admission World Federation of Neurological Surgeons grade, pre-existing hypertension, intracerebral hematoma, intraventricular hemorrhage, location of aneurysm, size of aneurysm, and mode of aneurysm treatment. In none of the subgroups did the magnesium sulfate group show a better outcome at 6 months.

Conclusions— The results do not support a clinical benefit of intravenous magnesium sulfate infusion over placebo infusion in patients with acute aneurysmal subarachnoid hemorrhage.

Long-term cognitive and psychological outcomes in the awakening and breathing controlled trial

RATIONALE

Studies have shown that reducing sedation of critically ill patients shortens time on the ventilator and in the intensive care unit (ICU). Little is known, however, of how such strategies affect long-term cognitive, psychological, and functional outcomes.

OBJECTIVES

To determine the long-term effects of a wake up and breathe protocol that interrupts and reduces sedative exposure in the ICU.

METHODS

In this a priori planned substudy conducted at one tertiary care hospital during the Awakening and Breathing Controlled Trial, a multicenter randomized controlled trial, we assessed cognitive, psychological, and functional/quality-of-life outcomes 3 and 12 months postdischarge among 180 medical ICU patients randomized to paired daily spontaneous awakening trials with spontaneous breathing trials (SBTs) or to sedation per usual care plus daily SBTs.

MEASUREMENTS AND MAIN RESULTS

Cognitive impairment was less common in the intervention group at 3-month follow-up (absolute risk reduction, 20.2%; 95% confidence interval, 1.5-36.1%; P = 0.03) but not at 12-month follow-up (absolute risk reduction, -1.9%; 95% CI, -21.3 to 27.1%; P = 0.89). Composite cognitive scores, alternatively, were similar in the two groups at 3-month and 12-month follow-up (P = 0.80 and 0.61, respectively), as were symptoms of depression (P = 0.59 and 0.82) and posttraumatic stress disorder (P = 0.59 and 0.97). Activities of daily living, functional status, and mental and physical quality of life were similar between groups throughout follow-up.

CONCLUSIONS

In this trial, management of mechanically ventilated medical ICU patients with a wake up and breathe protocol resulted in similar cognitive, psychological, and functional outcomes among patients tested 3 and 12 months post-ICU. The proven benefits of this protocol, including improved 1-year survival, were not offset by adverse long-term outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT 00097630).

Hypothermia as a cytoprotective strategy in ischemic tissue injury

Hypothermia is a well established cytoprotectant, with remarkable and consistent effects demonstrated across multiple laboratories. At the clinical level, it has recently been shown to improve neurological outcome following cardiac arrest and neonatal hypoxia-ischemia. It is increasingly being embraced by the medical community, and could be considered an effective neuroprotectant. Conditions such as brain injury, hepatic encephalopathy and cardiopulmonary bypass seem to benefit from this intervention. It's role in direct myocardial protection is also being explored. A review of the literature has demonstrated that in order to appreciate the maximum benefits of hypothermia, cooling needs to begin soon after the insult, and maintained for relatively long period periods of time. In the case of ischemic stroke, cooling should ideally be applied in conjunction with the re-establishment of cerebral perfusion. Translating this to the clinical arena can be challenging, given the technical challenges of rapidly and stably cooling patients. This review will discuss the application of hypothermia especially as it pertains to its effects neurological outcome, cooling methods, and important parameters in optimizing hypothermic protection.

Clinical study on cognitive dysfunction after spontaneous subarachnoid haemorrhage: patient profiles and relationship to cholinergic dysfunction

PURPOSE

We aimed to explore the cognitive profiles of subarachnoid haemorrhage patients who returned to the community, along with the associated risk factors.

METHODS

We recruited 40 Chinese patients with spontaneous subarachnoid haemorrhage 7-27 months after the initial presentation. They had all been discharged to their homes or to care homes for the elderly. For cognitive assessment, we employed the Cognitive Subscale of the Alzheimer Disease Assessment Scale (ADAS-cog) for global cognitive function, the Frontal Assessment Battery (FAB) for frontal lobe function, and the Rivermead Behavioural Memory Test (RBMT) for everyday memory function.

RESULTS

An ADAS-cog of more than 21/85 (poor global cognitive function) was noted in 14 (35%) patients. A FAB of less than 12/18 (poor frontal lobe function) was noted in 13 (27.5%) patients. An RBMT score of less than 15/26 (poor everyday memory function) was noted in 17 (43.6%) patients. Poor cognitive function was found to be associated with chronic hydrocephalus (in terms of FAB), with clinical vasospasm (in terms of RBMT), and with cerebral infarction (in terms of RBMT).

CONCLUSIONS

Poor cognitive function was common and occurred in up to 43.6% of the patients, with the verbal and behavioural memory aspects predominantly affected. We did not find a significant association between cholinergic dysfunction and cognitive dysfunction. Organization of future drug trials and cognitive rehabilitation should take into account the association between frontal lobe dysfunction and chronic hydrocephalus.

PREDICTORS OF GLOBAL COGNITIVE IMPAIRMENT 1 YEAR AFTER SUBARACHNOID HEMORRHAGE

OBJECTIVE

We sought to determine the frequency, risk factors, and impact on functional outcome and quality of life (QOL) of global cognitive impairment 1 year after subarachnoid hemorrhage.

METHODS

We prospectively evaluated global cognitive status 3 and 12 months after hospitalization with the Telephone Interview for Cognitive Status in 232 subarachnoid hemorrhage survivors. Cognitive impairment was defined as a score of 30 or less (scaled 0 = worst, 51 = best). Logistic regression was performed to calculate adjusted odds ratios (AORs) for impairment at 1 year. Basic activities of daily living were evaluated with the Barthel Index, instrumental activities of daily living were assessed with the Lawton scale, and QOL was evaluated with the Sickness Impact Profile.

RESULTS

The frequency of cognitive impairment was 27% at 3 months and 21% at 12 months. After the effects of age, education, and race/ethnicity were controlled for, risk factors for cognitive impairment at 12 months included anemia treated with transfusion (AOR, 3.4; P = 0.006), any temperature level higher than 38.6°C (AOR, 2.7; P = 0.016), and delayed cerebral ischemia (AOR, 3.6; P = 0.01). Among cognitively impaired patients at 3 months, improvement at 1 year occurred in 34% and was associated with more than 12 years of education and the absence of fever higher than 38.6°C during hospitalization (P = 0.015). Patients with cognitive impairment at 1 year had worse concurrent QOL and less ability to perform instrumental and basic activities of daily living (all P < 0.001).

CONCLUSION

Global cognitive impairment affects more than 20% of subarachnoid hemorrhage survivors at 1 year, is predicted by fever, anemia treated with transfusion, and delayed cerebral ischemia, and adversely affects functional recovery and QOL.

Use of prolonged hypothermia to treat ischemic and hemorrhagic stroke

Therapeutic (induced) hypothermia (TH) has been extensively studied as a means to reduce brain injury following global and focal cerebral ischemia, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). Here, we briefly review the clinical and experimental evidence supporting the use of TH in each condition. We emphasize the importance of systematically evaluating treatment parameters, especially the duration of cooling, in each condition. We contend that TH provides considerable protection after global and focal cerebral ischemia, especially when cooling is prolonged (e.g., >24 h). However, there is presently insufficient evidence to support the clinical use of TH for ICH and SAH. In any case, further animal work is needed to develop optimized protocols for treating cardiac arrest (global ischemia), and to maximize the likelihood of successful clinical translation in focal cerebral ischemia.

Perioperative hypothermia: use and therapeutic implications

Perioperative cerebral ischemic insults are common in some surgical procedures. The notion that induced hypothermia can be employed to improve outcome in surgical patients has persisted for six decades. Its principal application has been in the context of cardiothoracic and neurosurgery. Mild (32-35 degrees C) and moderate (26-31 degrees C) hypothermia have been utilized for numerous procedures involving the heart, but intensive research has found little or no benefit to outcome. This may, in part, be attributable to confounding effects associated with rewarming and lack of understanding of the mechanisms of injury. Evidence of efficacy of mild hypothermia is absent for cerebral aneurysm clipping and carotid endarterectomy. Deep hypothermia (18-25 degrees C) during circulatory arrest has been practiced in the repair of congenital heart disease, adult thoracic aortas, and giant intracranial aneurysms. There is little doubt of the protective efficacy of deep hypothermia, but continued efforts to refine its application may serve to enhance its utility. Recent evidence that mild hypothermia is efficacious in out-of-hospital cardiac arrest has implications for patients incurring anoxic or global ischemic brain insults during anesthesia and surgery, or perioperatively. Advances in preclinical models of ischemic/anoxic injury and cardiopulmonary bypass that allow definition of optimal cooling strategies and study of cellular and subcellular events during perioperative ischemia can add to our understanding of mechanisms of hypothermia efficacy and provide a rationale basis for its implementation in humans.

[Hypothermia for intracranial hypertension]

There is a large body of experimental evidence showing benefits of deliberate mild hypothermia (33-35 degrees C) on the injured brain as well as an improvement of neurological outcome after cardiac arrest in humans. However, the clinical evidence of any benefit of hypothermia following stroke, brain trauma and neonatal asphyxia is still lacking. Controversial results have been published in patients with brain trauma or neonatal asphyxia. Hypothermia can reduce the elevation of intracranial pressure, through mechanisms not completely understood. Hypothermia-induced hypocapnia should have a role on the reduction of intracranial pressure. The temperature target is unknown but no additional benefit was found below 34 degrees C. The duration of deliberate hypothermia for the treatment of elevated intracranial pressure might be at least 48 hours, and the subsequent rewarming period must be very slow to prevent adverse effects.

Posttraumatic stress disorder explains reduced quality of life in subarachnoid hemorrhage patients in both the short and long term

OBJECTIVE

A subarachnoid hemorrhage reduces patients' quality of life (QoL) in both the short and long term. Neurological problems alone cannot explain this reduction. We examined whether posttraumatic stress disorder (PTSD) and fatigue provide an explanation.

METHODS

We prospectively studied a representative sample of 105 subarachnoid hemorrhage patients. Patients were examined at approximately 3 and 13 months postictus. Examinations included assessments of PTSD, fatigue, sleep, cognitive and physical outcomes, and QoL. Patients' coping skills were also assessed. Regression analyses identified predictors for QoL and PTSD.

RESULTS

Thirty-seven percent met the diagnostic criteria for PTSD at both assessment points. This is a fourfold increase compared with the rate of PTSD in the general population. Fatigue in patients was also consistently elevated, higher, in fact, than the notoriously high fatigue level reported for cancer patients undergoing chemotherapy. PTSD was the best predictor for mental QoL, the domain most persistently impaired. It also helped predict physical QoL. Moreover, PTSD was linked to increased sleep problems and may, therefore, have led to fatigue in both the acute and later stages of recovery. To establish the cause of PTSD, a logistic regression was performed. This showed that maladaptive coping was the best predictor of PTSD.

CONCLUSION

PTSD explains why some subarachnoid hemorrhage patients, despite relatively good clinical outcomes, continue to experience a reduced QoL. Given that maladaptive coping skills seem the main cause of PTSD, teaching patients better coping skills early on might prevent PTSD and QoL reduction.

[Influence of age, gender, and severity on recovery of patients with brain injury]

PURPOSE

This study was conducted to investigate the individual and cross influences of age, gender, and severity on recovery of patients with brain injury.

METHODS

For the purpose of the study, traumatic or spontaneous brain injury patients admitted to the intensive care unit (ICU) were conveniently selected. The data regarding outcomes were collected 3 months after admission.

RESULTS

Individual influences of the study variables on patients' recovery were significant, except for gender. But while the individual influence of gender on recovery was not significant, cross influence of gender and age was significant, but only for the sub-dimension of 'arousalbility and awareness'. The study results also showed that 3-way cross influence of gender, age, and severity was only significant on the sub-dimension of 'arousalbility and awareness'.

CONCLUSION

The sub-dimension of recovery cross influenced by the demographic factors of gender and age, and severity was 'arousalbility and awareness'. This might indicate that the study variables that cross influencing recovery had more influence on consciousness compared to physical function and psycho-social adaptation.

Induced hypothermia and fever control for prevention and treatment of neurological injuries

Increasing evidence suggests that induction of mild hypothermia (32-35 degrees C) in the first hours after an ischaemic event can prevent or mitigate permanent injuries. This effect has been shown most clearly for postanoxic brain injury, but could also apply to other organs such as the heart and kidneys. Hypothermia has also been used as a treatment for traumatic brain injury, stroke, hepatic encephalopathy, myocardial infarction, and other indications. Hypothermia is a highly promising treatment in neurocritical care; thus, physicians caring for patients with neurological injuries, both in and outside the intensive care unit, are likely to be confronted with questions about temperature management more frequently. This Review discusses the available evidence for use of controlled hypothermia, and also deals with fever control. Besides discussing the evidence, the aim is to provide information to help guide treatments more effectively with regard to timing, depth, duration, and effective management of side-effects. In particular, the rate of rewarming seems to be an important factor in establishing successful use of hypothermia in the treatment of neurological injuries.